OK, i've just installed 2 jl's into my car...all the wiring work done...but i cant find where to ground it to...atleast thats what i think the problem is.....the amp IS getting power becasue the light is on, but when i take the ground wire and screw it in, it will just tap the sub, nothing really "hits".....i HAVE sanded and tried about 4 diffferent places....imput PLEASEEEEEE....thanks

BK

well, the easiest and probably best place to ground anything in the back is one of the rear-seat mounting brackets. if you just want to test out to make sure the amp is OK, you can ground to the spare tire hold down screw as well.

describe what is happening in more detail though....you say the amp turns on, but the subs dont sound loud? or do they just "thump" once and not make anymore sound?

they just barley "bump"..like i can barly hear em......and its pissin me off x(

btw...i tried the spare tire thing...once again they barley "thump"...But the amp DOES get power...cause the light goes on when i ground it...thanks

hmmm...ok. do you have more than one pair of RCA outputs on your headunit (even if they are running to another amp)? try connecting those to the input on the sub amp and see if it sounds better. if it does, youve burnt out the original set of RCA outputs you had. theres three possible causes to the problem youre having:

1) the signal being delivered to the amp is too low to properly amplify with any results. this would be caused by a low headunit volume level (duh) or a low voltage being sent by the headunit (to the amp), which could be a result of bad outputs on the headunit.

2) the amp is messed up internally. the only way to diagnose this is to rule out everything else.

3) the signal is being interuppted between the amp and the speakers. this is very very unlikly. if you had a short in the wire, the amp would either not work at all or go into protection mode.

if you dont have another set of RCA outputs, or want somthing more simple to wire up, hook up a walkman/cd player/etc headphone output, or prefereably, speaker output, considering those carry more voltage (using a 1/4" to RCA plug adapter) to the input of the amp. if the amp begains to work more correctly, you know the problem is somwhere upstream, so it could be in the headunit, an eqs you have, etc. i have a sneeking suspition youve burnt out an RCA output.


edit: i forgot to add that a poor set of RCAs running between the headunit and the amp could be the culprit as well, although its still unlikly. if all the above doesnt help, try replacing them.

i just got a new head unit, and wiring kit....the subs and amp are used....we hoked up the subsw to my friends car and they hit like the was no tommorow.....i doubt if its the head unit...also i doubt if its the rca cables....is it possible to burn new ones out that quickly?...thanks i really appreciate you taking time out to respond.....:thumbsup

even though the headunit may be new, an improper ground on the amp when first installing it may have caused the amp to ground out through the RCAs, then through the headunit, eventually leading to the destruction of the headunit outputs. it only takes a few minutes at most for this to happen, and it happens ALL the time. the first symptom of such is a very low output, which in your case seems to fit very well with your symptoms. in almost every post ive written recently in this forum, ive discussed this concept (for those regulars...I KNOW...IM BEING REPETATIVE!! ;) ), but because youre new i dont blame you for not knowing what im talking about. ;)

if the headunit outputs have been harmed, they are sending out a very low voltage signal to the amp, which in turn results in a low output by the amp.

youve already determined that the subs arent at fault, so you can start working backwards from there. try installing you amp in a known working enviroment. if that works, the problem MUST lie upstream (ie, within the headunit). that is why i suggested playing a walkman, etc. through the inputs of the amp, as this will eliminate the headunit from the equasion (cant spell).

What are the gains set on the amp? If the gains are all the way down, that could be the problem. Also what is the voltage rating of the HU? I know some HU have barely 2volts of output, when the high end HU's have atleast 4volts. Could be something as simple as that. I agree with SPL_Eclipse, it's either a problem with the HU or a problem with the amp.

thanks for your imput guys.....i'll try all your thought out this weekend.....me and "RSCLIPSE9d7" are workin on it....so we'll c...he knows his shit.....thansk for the thoughts guys i app. it....peace:thumbsup

We got it to work.... thanks for all the help guys. If Brian wants to tell everyone what was wrong I will let him. :)

I know this sounds dumb, but are your gains turned up? i did that b4, was pissed for like 2 hrs trying to figure out what was wrong. then dought! in my best homer simpson.. haha turned the gains up.. and bump bump bump.